AU2008212895B2 - Two-component adhesive - Google Patents

Abstract

Two-component adhesive for bonding wood materials, comprising an isocyanate-containing component A and an amine-containing component B, component A comprising an isocyanate-terminated prepolymer having an isocyanate functionality of ≥ 1.7, preferably of 1.7 < f

Description

WO 2008/095915 PCT/EP2008/051381 1 Two-component adhesive The invention relates to a two-component adhesive for bonding wood materials. In recent times polyurethane adhesives have frequently been used for the bonding of wood materials, including, more particularly, in load-bearing glued wood construction (civil engineering wood construction) such as, for example, for the fabrication of 10 construction members (glued laminated beams, wall elements, etc.). In such applications both two-component and one component, moisture-curing systems are employed. In the case of the latter systems, application of the adhesive is followed by a preliminary reaction between isocyanates and moisture from the is ambient air or from the substrate: from part of the isocyanate used, with elimination of carbon dioxide, the corresponding amine is formed, and subsequently reacts with isocyanate to produce a urea bond, eliminating C02 as it does so. 20 The reaction of aromatic isocyanates and hydroxyl groups (from water or alcohols) is faster by several orders of magnitude than the corresponding reaction of aliphatic isocyanates. However, the aromatic system makes aromatic isocyanates susceptible to oxidation and intrinsically less lightfast. In certain 25 applications, moreover, the urethane reaction is still not quick enough - as, for example, for mass production of assembled parts with high throughput. There are limits on acceleration in the case of one-component systems in any case. First, the diffusion of the water molecules from the substrate or from the air is so often rate-determining. Second, highly accelerated formulations have a tendency to form foam, since the C02 formed remains enclosed. For numerous applications, particularly in the exterior sector, moreover, high heat resistance and water C NRPortbl)CCRBRU67U_ I DOC-16/ll/2012 2 resistance qualities are required. The present invention, therefore, seeks to address the disadvantages of the known art and thus, more particularly, 5 aims to provide a two-component adhesive for bonding wood materials that allows bonds to be accomplished which very rapidly acquire a load-bearing capacity. The strength and resistance properties of the resulting bond can be at least similar to, if not, better than, those as known for the 10 polyurethane adhesives discussed above. Moreover, the two component adhesive ought to be extremely lightfast. In one aspect, the present invention therefore provides a two component adhesive for bonding wood materials, which comprises 15 an isocyanate-containing component A and an amine-containing component B. Component A here comprises an isocyanate terminated prepolymer or prepolymer mixture having an isocyanate functionality of 1.7, preferably of 1.7 < fNCO < 3, more preferably in the range from 2 to 3. With particular 20 preference the isocyanate-terminated prepolymer or prepolymer mixture is liquid or pasty at room temperature (200C), but not solid. The isocyanate content of the prepolymer is more particularly 6% to 33%, preferably 8% to 25%, more preferably 12% to 18% by weight. Component B comprises at least one 25 diamine and/or polyamine, preferably a polyetherdiamine and at least one polyetherpolyamine, wherein the stoichiometric ratio of isocyanate groups in component A to amine groups in component B is about 0.5 to 1.2. With particular preference component B, more particularly the diamine and/or polyamine, is 30 liquid or pasty at room temperature (20 0 C), but not solid. With further preference component B contains substantially no hydroxyl groups. Accordingly, in the two-component adhesive the crosslinking of 35 the isocyanate-containing prepolymer of component A is brought C:\NRPorth\DCC\RBR\4,211 I I D0C I- 111/21 2 about by means of amines which are provided systematically in component B. This results in a plurality of advantages as compared with the prior art: (1.) In comparison to the one component polyurethane systems described above, there is no 5 need first to generate amines by hydrolysis of excess isocyanate - instead, the amines are provided as such, which massively accelerates the reaction. The moisture contents of the substrates and/or of the air are therefore not relevant for the bonding process. As a result it is also possible to bond 10 substrates such as glass, metals, etc. without problems. The absence of CO 2 is likewise beneficial for the bond, since there is no need for opposing pressure and there are also no bubbles to weaken the cohesion of the joint. (2.) In comparison to the two-component polyurethane systems described above it is 15 possible, if lightfastness is required, to use, appropriately, exclusively aliphatic amines, which also leads to crosslinking which tends to be quicker, with the formation of urea bridges. By virtue of the present invention, therefore, without a loss of quickness in the reaction system, and instead, in fact, with 20 acceleration, it becomes possible to omit very largely - and preferably completely - aromatic amines, more particularly polymers containing aminobenzoate. In the case of mechanical processing, it is possible to achieve very short cycle times in bonding. Moreover, there is no need at all for the presence of 25 monoamines. Surprisingly, in addition, ceteris paribus, probably because of the greater thermodynamic stability of the urea bond as compared with the urethane bond, increases in the heat stability and water resistance are obtained. 30 In particularly preferred embodiments the isocyanate-terminated prepolymer or prepolymer mixture in component A is a polyurethane or polyurea prepolymer, where appropriate as a WO 2008/095915 PCT/EP2008/051381 4 blend with further isocyanates, examples being monomeric diisocyanates, polymeric isocyanates, or monofunctional isocyanates. Where appropriate it is also possible to do entirely without the presence of prepolymers and, instead, the corresponding reactants (diisocyanates/polyisocyanates on the one hand and diols/polyols and/or diamines/polyamines on the other) for the generation of a prepolymer can be present in component A. Polyurethane prepolymers and/or polyurethane prepolymer mixtures are preferred in the context of the 10 invention: they allow the effective adhesion, known from the above-discussed prior art, of polyurethane compositions to wood materials to be utilized further. Suitable polyurethane or polyurea prepolymers and their i5 preparation are known per se to the skilled person. Mention is made in particular of: ISOCYANATES 20 Polyisocyanates are essential for the preparation of polyurethanes and polyureas. The general empirical formula of polyisocyanates is R-(NCO)n, with n 2, and with R denoting an aromatic or aliphatic group. Polyisocyanates that react with hydroxyl groups form polyurethanes; polyisocyanates that react with amine groups form 2b polyureas. Polyisocyanates used are preferably diisocyanates, with particular preference selected from the group consisting of 4,4' methylenebis(phenyl isocyanate) (MDI); tolylene diisocyanate (TDI); 30 m-xylylene diisocyanate (XDI); hexamethylene diisocyanate (HDI); methylenebis(4-cyclohexyl diisocyanate) (HDMI); naphthalene 1,5 diisocyanate (NDI); 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI); 1,4-diisocyanatobenzene (PPDI), phenyl 1,4-diisocyanate; trimethylhexamethylene diisocyanate (TMDI); isophorone diisocyanate 3, (IPDI); 1,4-cyclohexyl diisocyanate (CHDI); diphenyl ether 4,4'- WO 2008/095915 PCT/EP2008/051381 5 diisocyanate; p,p'-diphenyl diisocyanate; lysine diisocyanate (LDI); 1,3-bis(isocyanatomethyl)cyclohexane; polymethylpolyphenyl isocyanate (PMDI); and isomers and/or mixtures thereof. 5 Particular preference is given to MDI and polyMDI mixtures. Methylene-bridged polyphenyl polyisocyanate mixtures normally contain about 20 to about 100 per cent by weight of MDI isomers (typically about 20 to about 95 per cent by weight of which are accounted for by the 4,4' isomer), the remainder being formed by 10 polymethylenepolyphenyl isocyanates of higher functionality (typically approximately between 2.1 and 3.5) and higher molecular weight. Isocyanate mixtures of this kind are available commercially and/or can easily be prepared in accordance with US 3,362, 979. 15 The isocyanates can of course be used in the form of higher homologues, such as in isocyanurate, carbodiimide, allophanate, biuret or uretdione form, for example. 20 PREPOLYMERS Polyurethane prepolymers Polyurethane prepolymers are prepared by reacting polyols with 25 the abovementioned isocyanates. Suitable polyols are familiar to the skilled person. In the context of the invention they typically have a molecular weight of about 500 to about 6000 and/or two to four hydroxyl groups. Particularly preferred polyols are polyesters, polyethers, polythioethers, polyacetals 30 and polycarbonates having in each case two to four hydroxyl groups. Preferred polyethers in the context of the invention are known per se to the skilled person and can be prepared, for example, by polymerizing epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide WO 2008/095915 PCT/EP2008/051381 6 or epichlorohydrin in the presence of BF3, or by addition of epoxides, more particularly of ethylene oxide or propylene oxide, to molecules containing reactive hydrogens, such as water, alcohol or amines, for example (examples being low 5 molecular weight diols, triols or tetraols; 4,4'-di hydroxydiphenylpropane; aniline; ammonia; ethanolamine; ethylenediamine). Polypropylene glycol and polytetramethylene glycol (PTMG or PTMEG) are presently preferred. 10 In prepolymer preparation it is also possible to employ chain extenders that are known per se, more particularly diols/polyols of low molecular weight (typically less than 400 g/mol) . Mention may be made in particular of ethylene glycol, propylene glycol, butane glycol, pentane glycol, hexane glycol, benzyl glycol, i5 xylene glycol, water, 1,4-butanediol, 1,3-butanediol, 2,3 dimethyl-2,3-butanediol, dipropylene glycol and tripropylene glycol, diethylene glycol and triethylene glycol, N-N'-bis(2 hydroxypropyl)aniline (DHPA), 1,4-di (2-hydroxyethyl)hydroquinone (HQEE), diethanolamine, triethanolamine, trimethylolpropane and 20 glycerol. Polyalkenylpolyols, polyetherpolyols or polyesterpolyols or mixed polyesterpolyetherpolyols having preferably 2 or 3 hydroxyl end groups can be reacted with a well-defined excess of 25 isocyanates to give NCO-terminated urethane prepolymers. They are also available commercially, for example from BAYER AG, e.g. under the commercial brand names Desmodur® E22 or E23. Distilled products, where the removal of the excess diisocyanate leads to fNCO = 2, are likewise known and can be used. 30 Polyurea prepolymers Polyurea prepolymers are prepared in conventional manner by WO 2008/095915 PCT/EP2008/051381 7 reacting polyamines having 2 amine groups with a well-defined excess of difunctional or polyfunctional isocyanate compounds to give NCO-terminated urea prepolymers. In the context of the invention, however, polyurea prepolymers , are less preferred than polyurethane prepolymers, since they tend to gel at room temperature as a result of the formation of hydrogen bonds. AMINES 10 Polyetherpolyamines As a polymeric polyamine component it is possible with preference to use compounds having a functionality of 2 to 4, i5 with more than 50% of the active hydrogen atoms, more particularly, being formed by primary or secondary amines. Mention may be made in particular of the following: polyoxyalkylenamines such as, for example, polyoxypropylene diamines, polyoxyethylenediamines, polytetramethylene ether 20 diamines, polyoxypropylenetriamines, polyoxyethylenetriamines (known under the trade name Jeffamine@ from Huntsman); and also, if aromatic components are tolerable for a specific application, the following: polyethylene glycol di(p-aminobenzoate); polyethylene glycol di(o-aminobenzoate); polyethylene glycol zb di(m-aminobenzoate); polytetramethylene glycol di(p-amino benzoate); polytetramethylene glycol di(o-aminobenzoate), polytetramethylene glycol di(m-aminobenzoate). As polyamines it is possible to use polyethylene oxide-polypropylene oxide polyethers, more particularly those having a functionality of 30 approximately two to approximately three and/or having a molecular weight of approximately 200 g/mol to approximately 6000 g/mol (described, for example, in US 4,433,067). It is also possible of course to use mixtures of amine-terminated WO 2008/095915 PCT/EP2008/051381 8 polyethers in the context of the invention. Preference is given to using polyoxyalkylenediamines having an average molecular weight in the range from about 150 g/mol to , about 7500 g/mol, preferably in the range from about 250 g/mol to about 6000 g/mol. Amines as chain extenders 10 In the context of the invention it is also possible to use aminic chain extenders, preferably those having a molecular weight of typically less than 400 g/mol. Mention may be made in particular of aliphatic diamines, as described for example in US 4,246,363 and US 4,269,945. Additionally, a chain-extending i aliphatic diamine can be selected from the group consisting of ethylenediamine; neopentanediamine; 1,2- and 1,3-propanediamine; 1,6-hexamethylenediamine; 1,8-octamethylenediamine; 1,12-dodeca methylenediamine; cyclohexyldiamine; 4,4'-bis(para-aminocyclo hexyl)methane; 2,2'-dimethyl-4,4'-methylenebis(cyclohexylamine) 20 (dimethyldicyclane); isophoronediamine; 4,7-dioxadecane-1,10 diamine; 4,7,10-trioxadecane-1,13-diamine, tetramethylethylenediamine; pentamethyldiethylenetriamine; dimethylcyclohexylamine; tetramethyl 1,3-butanediamine; pentamethyldipropylenetriamine; bis(dimethylamino ethyl ether) triethylene glycol diamine; 4,4' -methylenebis (2-ethyl-6 2b methylcyclohexylamine) (M-MECA); 4,4'-methylenebis(2,6-diethyl cyclohexylamine) (MDECA); 4,4'-bis(sec-butylamino)dicyclohexylmethane (available commercially as Clearlink@ 1000) and monomers thereof; 3,3'-dimethyl-4,4'-bis(sec-butylamino)dicyclohexylmethane (available commercially as Clearlink@ 3000) and monomers thereof; N,N' 30 diisopropylisophoronediamine (available commercially as Jefflink@ 754); amines of aspartamic acid such as, for example, N,N'-diethyl maleate-2-methylpentamethylenediamine (available commercially as Desmophen® NH-1220), N,N'-diethyl maleate-aminodicyclohexylmethane (available commercially as Desmophen@ NH-1420), and N,N'-diethyl 35 maleate-aminodimethyldicyclohexylmethane (available commercially as WO 2008/095915 PCT/EP2008/051381 9 Desmophen@ NH-1520). Aromatic diamines as well (as described for example in US 4,659,747) can be used as chain extenders in the context of the , invention, subject to the proviso of the aforementioned light stability requirements for certain applications. The following may be mentioned specifically: dimethylbenzylamine; diethylbenzylamine; 1,2-dimethylimidazole; 2-methylimidazole; 1,2-, 1,3- or 1,4-bis(sec-butylamino)benzene (available 10 commercially as Unilink@ 4100); 4,4'-bis (sec-butylamino)di phenylmethane (available commercially as Unilink@ 4200); trimethylene glycol di(p-aminobenzoate) (available commercially as Versalink 740M); trimethylene glycol di(o-aminobenzoate); trimethylene glycol di(m-aminobenzoate); polyethylene glycol is di(p-aminobenzoate); polyethylene glycol di(o-aminobenzoate); polyethylene glycol di(m-aminobenzoate); polytetramethylene glycol di(p-aminobenzoate); polytetramethylene glycol di(o aminobenzoate); polytetramethylene glycol di(m-aminobenzoate); aromatic diamines such as, for example, 3,5-diethyl-2,4 20 toluenediamine and 3,5-diethyl-2,6-toluenediamine (available commercially as Ethacure@ 100) and 3,5-dimethylthio-2,4 toluenediamine and 3,5-dimethylthio-2,6-toluenediamine (available commercially as Ethacure@ 300); 4,4'-methylenebis(2 chloroaniline); diethylenetriamines; triethylenetetramines; 25 tetraethylenepentamine; methylenedianiline (MDA); m-phenylene diamine; diethyltoluenediamine; 4,4'-methylenebis(3-chloro-2,6 diethylbenzylamine) (MCDEA); diethyltoluenediamines (DETDA); 4,4'-methylenebis(2-ethyl-6-methylanilines) (NMMEA); 4,4' methylenebis(2, 6-diethylaniline) (MDEA); 4,4'-methylenebis(2 so isopropyl-6-methylaniline) (MMIPA); 4,4'-bis (sec-butylamino) diphenylmethanes; phenylenediamines; methylenebis-ortho chloroaniline (MBOCA); 4,4'-methylenebis(2-methylaniline) (MMA); 4,4'-methylenebis(2-chloro-6-ethylaniline) (MCEA); 1,2-bis(2 aminophenylthio)ethane; N,N'-dialkyl-p-phenylenediamine; 4,4'- WO 2008/095915 PCT/EP2008/051381 10 methylenebis(2,6-diisopropylaniline) (MDIPA); and dimethylthiotoluenediamine (2,4 and 2,6 isomers) (DMTDA); 4-chloro-3,5-diaminobenzoic acid isobutyl ester (CDABE), and mixtures thereof. The mixing ratio of the aforementioned chain extenders with the polyamines can easily be harmonized in routine tests by the skilled worker to the desired proportion of hard segments and soft segments. In this case account should be taken of the 10 customary art requirements concerning the miscibility of the components. The aforementioned primary polyamines can be modified further in the context of the invention in a manner which is customary in i5 the art, such as, for example, with epoxides (US 6,723,821), with acrylates (via a Michael addition, as described, for example, in US 5,359,123 and US 5,192,814), or else with alkoxysilanes (preferably with aminosilanes, as described, for example, in WO 02059224), and also with isocyanatosilanes, 20 epoxysilanes or acrylatosilanes. Through the incorporation of the alkoxysilyl compounds into the isocyanate component and/or amine component it is possible to obtain these 2K polyurea adhesives with an improved profile of 25 properties in terms of adhesion, water resistance or acid resistance. Particularly preferred amines in component B are polyoxypropylenediamines, preferably those having an average so molecular weight of about 2000 g/mol (available commercially, for example, under the trade name Jeffamine@ D-2000 as per CAS 9046-10-0; Huntsman Corporation, Houston, Texas); primary, branched polyethertriamines, preferably having an average C NRPonbl\DCC\RBR4U6732 _ I DOC-16111/2112 11 molecular weight of about 5000 g/mol (available commercially, for example, under the trade name Jeffamine® T-5000 as per CAS 64852-22-8; Huntsman Corporation, Houston, Texas (USA)); substituted, more particularly aromatic diamines such as, for 5 example, diethyltoluenediamine (available commercially under the trade name Harter DT or Harter VP LS 2214; Bayer AG, Leverkusen (DE)) or N,N'-dialkylaminodiphenylmethane (available commercially under the trade name Unilink'" 4200 Diamine; UOP GmbH, Erkrath (DE)). 10 The functionality of the NCO-terminated prepolymers, more particularly of the urethane prepolymers, is 1.7, preferably 1.7 < fNCO < 3, more preferably in the range from 2 to 3. Functionalities > 2 are explained not only by additionally 15 present, free isocyanates but also by allophanate groups, which can come about through reaction of urethane groups with further NCO units; prepolymers of this kind are therefore often referred to in the art as "quasi-prepolymers". In the course of the further reaction of component B, allophanate groups in 20 component A are cleaved back into a urethane and free isocyanate. The stoichiometric ratio of isocyanate groups in component A to amine groups in component B is about 0.5 to about 2, preferably 25 about 0.9 to about 1.2, more preferably about 1. By way of the selection and, where appropriate, combination of different diamines or polyamines it is easily possible for the skilled person, in routine tests, to adjust key properties of 30 the two-component adhesive exclusively by way of component B, such as, for example, the elasticity, water resistance, reaction rate, etc.; component A, in contrast, can be retained, which allows considerable flexibility both from the production WO 2008/095915 PCT/EP2008/051381 12 standpoint, for the manufacturer, and in provision as well, for the user (system with different components B; see below). The compositions of the invention can of course comprise the further additives customary in the art, of the kind generally customary in the polyurethane/polyurea industry. For example: plasticizers, examples being esters of organic carboxylic acids or their anhydrides, phthalates such as dioctyl phthalate or diisodecyl phthalate, for example, adipates, such as dioctyl 10 adipate, for example, sebacates, organic phosphoric and sulphonic esters, polybutenes and other compounds that do not react with isocyanates; solvents; organic and inorganic fillers, such as, for example, ground or precipitated calcium carbonates, which if appropriate have been coated with stearates, or carbon i5 blacks, kaolins, aluminas, silicas and PVC powders; fibres, made of polyethylene or of polyamide, for example; pigments; rheology modifiers such as, for example, thickeners, examples being urea compounds, polyamide waxes, bentonites or fumed silicas; adhesion promoters, more particularly silanes such as 20 vinylsilanes, isocyanatosilanes in the isocyanate component and aminosilanes, reacted with aldehydes to form aldiminosilanes, in the amine component; siccatives such as, for example, p-tosyl isocyanate and other reactive monoisocyanates, vinyltrimethoxy silane, orthoformic esters, calcium oxide or molecular sieves 25 (e.g. zeolites); heat, light and UV radiation stabilizers; flame retardants; surface-active substances such as, for example, wetting agents, flow control agents, devolatilizers or defoamers; fungicides or fungal growth inhibitors; and also other substances commonly employed in the polyurethane industry. 30 With regard to such additives reference is made to Polyurethane Handbook 2nd edition, GfInter Oertel (Editor), Hanser Publishers Munich 1994, pages 98 to 128, whose disclosure content with C.\NRPonblDCC\BR\W3233_ DX'-il /~2I1 2 13 regard to additives common in the art is hereby included by reference as part of the disclosure content of the present invention . With aforementioned two-component adhesives it is readily 5 possible to meet various standard specifications in wood construction, as for example in the context of the processing of beech; for example: - a bond strength Cl to DIN EN 12765 (precise-fit joint) of > 1ON/mm>, preferably of 12N/mm 2 ; and/or 10 - a bond strength Cl to DIN EN 12765 (0.5mm joint) of 7.5N/mm 2 , preferably of 9N/mm 2 ; and/or - a water resistance C3 (conditioning sequence 3) to DIN EN 12765 (precise-fit joint) of 4N/mm 2 , preferably of 5N/mm 2 ; and/or 15 - a water resistance C3 to DIN EN 12765 (0.5mm joint) of 3N/mm 2 , preferably of 4N/mm 2 ; and/or - a heat resistance to DIN EN 14257 (precise-fit joint) of 7N/mm 2 , preferably of 9N/mm 2 . In another aspect, the present invention relates to a method of 20 bonding wood substrates, more particularly in structural wood construction, comprising applying an above-described two component adhesive to at least one of the substrates to be joined. Suitable further substrates include primarily the following: metals, glass, ceramic, plastics, textiles. With 25 particular advantage it is possible to use the compositions of the invention to bond glass, as set out above, since when aromatic constituents are not used very much, and more particularly not at all, it is possible to achieve outstanding lightfastness, with additional acceleration of the reaction as 30 compared with known polyurethane systems. A further aspect of the present invention relates to a method of producing a two-component adhesive comprising an isocyanate containing component A and an amine-containing component B, CNRPonbhIDCC\RBR\M71 2 . I DOC. 1(, 21 12 14 - component A comprising an isocyanate-terminated prepolymer having an isocyanate functionality of 1.7, preferably of 1.7 < fNCO < 3, more preferably in the range from 2 to 3; and 5 - component B comprising at least one diamine and at least one polyamine, preferably a polyetherdiamine and/or polyetherpolyamine, and wherein the stoichiometric ratio of isocyanate groups in component A to amine groups in component B is set to about 0.5 10 to about 2, preferably about 0.9 to about 1.2, more preferably about 1. The invention accordingly relates in a further aspect to the use of an isocyanate-containing component A and an amine containing component B, 15 - component A comprising an isocyanate-terminated prepolymer having at least two isocyanate groups, in particular one polyurethane prepolymer; and - component B comprising at least one diamine and/or polyamine, preferably a polyetherdiamine and/or 20 polyetherpolyamine, as a two-component adhesive for bonding wood materials, metals, glass, ceramics, plastics, textiles, and more particularly for the bonding of wood materials. No such use for these two components has hitherto been proposed in the art; the 25 surprising, advantageous properties in the context of their use as a two-component adhesive, more particularly in the bonding of wood materials, have been described above. The invention further relates to an assembly of components, more particularly construction members for structural wood 30 construction, the assembly having been produced substantially by means of a two-component adhesive as described above. Furthermore, in a further aspect, the invention relates to a system for the individualized provision of a two-component C NRPorbl)CC\RBR\4671231 IDOC-l6i/ l/2,12 15 adhesive more particularly for the bonding of wood materials, comprising - at least one component A, comprising an isocyanate terminated prepolymer (or a mixture of prepolymers) having 5 an isocyanate functionality of 1.7, preferably of 1.7 < fNCO < 3, more preferably in the range from 2 to 3; and - at least two alternative components B, each comprising at least one different diamine and at least one polyamine, preferably a polyetherdiamine and/or polyetherpolyamine, 10 wherein the stoichiometric ratio of isocyanate groups in compound A to amine groups in compound B is about 0.5 to about 2. By means of such a system (in the sense of an ordered provision for common use (kit of parts)) it is possible for a two 15 component adhesive of the invention to be provided in an individualized way, surprisingly simply and flexibly, exclusively via the component B to be chosen on the part of the user in a manner specific to the application. The invention is elucidated in greater detail below with 20 reference to working examples, without the subject matter of the invention being restricted to these embodiments. As component A, Desmodur® E23 from Bayer AG (Leverkusen, DE) was used. In the compositions described in more detail below, the 25 following mixtures were used as components B (viscosity, Brookfield, 20 0 C: approximately 250 mPa*s) Identification M 3 M 320 M 323 code: Jeffamine D- 21.25 21.25 21.25 2000 Jeffamine T- 3.75 3.75 3.75 5000 Unilink 4200 75 65 70 WO 2008/095915 PCT/EP2008/051381 16 HArter DT 10 5 Total 100.00 100.00 100.00 (All figures in g) The following two-component adhesives were produced: 5 Example 1: DesmodurO E23 + M3 Mixing ratio: (Vol.) 100 : 74.2, (wt.) 100 : 65.7 Potlife of 20 g of the mixture in the laboratory: 2 min 10 Potlife with mechanical mixing: 1 min 15 sec Example 2: DesmodurO E23 + M323 Mixing ratio: (Vol.) 100 : 71.0, i5 (wt.) 100 : 62.8 Potlife of 20 g of the mixture in the laboratory: 1 min 05 sec Potlife with mechanical mixing: 30 - 35 sec Example 3: 20 DesmodurO E23 ± M320 Mixing ratio: (Vol.) 100 : 67.9, (wt.) 100 : 60.1 Potlife of 20 g of the mixture in the laboratory: 1 min Potlife with mechanical mixing: 20 - 25 sec. 25 The following bonds (beech) were implemented using the abovementioned two-component adhesives and then analysed: Ex. 1 Ex. 2 Ex. 3 C1 EN 12765 (Target 10 N/mm 2 ) precise fit value at break 12.7 N/n 2 13.1 N/mm 2 11.6 N/mm 2 aspect at break 100% MF 100% MF 100% MF WO 2008/095915 PCT/EP2008/051381 17 joint 0.5 mm value at break 8.8 N/mm 2 9.2 N/n 2 Not aspect at break 100% MF 100% MF determined C3 EN 12765 (Target 4 N/mm 2 ) precise fit value at break 4.6 N/mm 2 4.4 N/mm 2 3.8 N/mm 2 aspect at break 100% AF 100% AF 100% AF joint 0.5 mm value at break 5. 42 N/n 2 2. 96 N/mm2 Not aspect at break 100% AF 100% AF determined EN 14257 (Target 7 N/mm 2 ) lh at 800C value at break 8.3 N/mm 2 9.2 N/mm 2 9.0 N/mm 2 aspect at break 95% AF 40% AF 70% AF 5% MF 60% MF 30% MF Cold storage 24h at 200C, broken cold value at break 11.2 N/mm 2 12.1 N/mm 2 12.0 N/mm 2 95% MF 85% MF 100% MF aspect at break 5% CF 15% AF HDF - HDF Cl EN 12765 Precise fit value at break 3.6 N/mm 2 3.9 N/rn 2 Not aspect at break 100% MF 100% MF determined Key: HDF: high-density fibreboard (Pavatex Homadur, untreated, 5 mm, sanded both sides); EN 14257: DIN EN 14257, September 2006 version; EN 12765: DIN EN 12765, September 2001 version; MF: fracture in material; CF: cohesive fracture of the adhesive layer; AF: adhesive fracture between adhesive and substrate. 10 The two-component adhesives of the invention display outstanding adhesive properties not only on wood. On glass and aluminium, as well, high strengths are obtained, as shown by the following examples: 15 Identification code: M16 M16b M6 M7 Jeffamine D-2000 21.25 11.58 21.25 12.50 Jeffamine T-5000 3.75 12.50 Unilink 4200 37.50 20.44 37.50 75.00 Harter DT 37.50 20.44 37.50 WO 2008/095915 PCT/EP2008/051381 18 Jeffamine T-403 3.75 2.04 Aerosil R 202 0.50 Siliporite SA 1720 5.00 Millicarb 40.00 where (unless already indicated earlier on above): DesmodurO E 305: largely linear NCO prepolymer based on hexamethylene diisocyanate and an ether diol, Bayer; JeffamineO T-403: polyoxypropylenetriamine (CAS 39423-51-3), Huntsman; AerosilO R 202: synthetic, hydrophobic silicon dioxide, Degussa; 10 Siliporite@ SA1720: molecular sieve (alkali metal and alkaline earth metal aluminosilicate; type A zeolite), CECA, Arkema Group; Millicarb@-OG: natural, very fine and readily dispersible CaCO3 in powder form, prepared from a pure, white limestone, Omya AG Desmodur Desmodur Desmodur Desmodur Comp. A E305 E305 E305 E23 Comp. B M 16 M 16b M 6 M 7 Mixing ratio 100 : 39.2 100 : 71.8 100 : 40.5 100 : 66.1 by weight Mixing ratio 100 : 42.7 100 : 78.3 100 : 44.1 100 : 74.7 by volume approx. 2 approx. 2 approx. 2 approx. 2 Potlife min 30 min 25 min min 30 Tensile shear strength 12.8; AF 18.2; 30% CF 11.8; AF 7.9; AF Al 21d Tensile shear strength > 6; MF 5.1; AF > 6; MF > 6; MF Glass 21d Tensile shear strength 13.2; 75- W 10.3; 100- W 12.7; 70- W 12.6; 60- W Wood 21d Strength data in MPa C\NRPonbl\DCC\RBR\4r7123_1 DOC-IWfl /2012 19 W: Break in wood Test equipment: Tensile testing machine Instron 5567; jaw separation rate 50 mm/min. 5 These tests show that the common view that sufficiently robust adhesive bonds cannot be produced using adhesives which react extremely rapidly is not true. Surprisingly, the relevant standards are met - and, in some cases, significantly exceeded - by the two-component adhesives of the invention. 10 Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step 15 or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it) , or to any matter which is 20 known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims (9)

1. Two-component adhesive for bonding wood materials, comprising an isocyanate-containing component A and an 5 amine-containing component B, - component A comprising an isocyanate-terminated poly urethane prepolymer having an isocyanate functionality of 1.7,; and - component B comprising at least one diamine and at 10 least one polyamine, and wherein the stoichiometric ratio of isocyanate groups in component A to amine groups in component B is about 0.5 to 1.2. 15 2. Two-component adhesive according to claim 1 further comprising one or more additives selected from plasticizers; solvents; organic and inorganic fillers; fibres; pigments; rheology modifiers; siccatives; heat, light and UV radiation stabilizers; flame retardants; 20 wetting agents; flow control agents; devolatilizers; defoamers; fungicides or fungal growth inhibitors; and mixtures thereof.

3. Two-component adhesive according to Claim 1 or 2, which, 25 when used for joining wood, allows obtaining: - a bond strength Cl to DIN EN 12765 (precise-fit joint) of 1ON/mm 2 ; and/or - a bond strength C1 to DIN EN 12765 (0.5mm joint) of >

7.5N/mm 2 ; and/or 30 - a water resistance C3 (conditioning sequence 3) to DIN EN 12765 (precise-fit joint) of 4N/mm 2 ; and/or - a water resistance C3 to DIN EN 12765 (0.5mm joint) of 3N/mm 2 ; and/or - a heat resistance to DIN EN 14257 (precise-fit joint) 35 of 7N/mm 2 . C \NRPonbIDCC\RBR\46723 I DOC-1611//212 21 4. Two-component adhesive according to any one of claims 1 to 3, when used to join beech. 5 5. Two-component adhesive according to claim 1, substantially as hereinbefore described. 6. Method of bonding wood substrates comprising the application of a two-component adhesive according to any 10 one of Claims 1 to 5 to at least one of the substrates to be joined. 7. Method of producing a two-component adhesive comprising an isocyanate-containing component A and an amine-containing 15 component B, - component A comprising an isocyanate-terminated polyurethane prepolymer having an isocyanate functionality of 1.7; and - component B comprising at least one diamine and at 20 least one polyamine, wherein the stoichiometric ratio of isocyanate groups in component A to amine groups in component B is set to about 0.5 to 1.2. 25 8. Method according to claim 7, substantially as hereinbefore described.

9. Use of an isocyanate-containing component A and an amine containing component B, 30 - component A comprising an isocyanate-terminated pre polymer having at least two isocyanate groups; and - component B comprising at least one diamine and at least one polyamine, wherein the stoichiometric ratio of isocyanate groups in 35 compound A to amine groups in compound B is about 0.5 to C:\NRPonh\DCC\HRU(,732 I DOC. 16,11/2012 22 1.2, as a two-component adhesive for bonding wood materials, metals, glass, ceramics, plastics, textiles.

10. Use of an isocyanate-containing component A and an amine 5 containing component B according to claim 9, as a two component adhesive for bonding wood materials.

11. Use according to claim 9, substantially as hereinbefore described. 10

12. Interconnection of components, wherein the interconnection has been produced substantially by means of a two component adhesive according to any one of Claims 1 to 5. 15 13. Interconnection of components according to claim 12, wherein the components are construction members for structural wood construction.

14. System for the individualized provision of a two-component 20 adhesive, comprising - at least one component A, comprising an isocyanate terminated polyurethane prepolymer having an isocyanate functionality of 1.7; and - at least two alternative components B, each 25 comprising at least one different diamine and at least one polyamine, and wherein the stoichiometric ratio of isocyanate groups in compound A to amine groups in compound B is about 0.5 to 1.2. 30 15. System for the individualized provision of a two-component adhesive according to claim 14, when used for the bonding of wood materials.

16. System according to claim 14, substantially as 35 hereinbefore described.